SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2dda2d880f0c535a58b6e63c51ff33fe51577c0fcdd193f2b1835f0360dba80' 
  AND token = 't/mIdOV/ZjernZJgqohyAIIjNR7iqkjEPMeFzVHc6C0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}