SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e923ab72fa9d31ffc63380311ae2709b0753126b8bd9a8d4924c25e9ebeefc0' 
  AND token = 'rx8ixQR1EnvJOexHpSldBVRhCZZvL8CjOmW1Z3kNHps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}