SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7477addd998498837be942c50288ea6dbd95a26615a747de2c89534de575f599' 
  AND token = 'T8aMHC2lQuV/sM9K2F2x/AAepBUmtfl2h3DaPM2aJzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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