SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a86a936db171f58c8de561eddd1edf71e4d667a5ea26cd029f3084a0c78cf05' 
  AND token = 'C10UXJw+i/otDKvCpwZXcQkISH4ISxttgaHS5av27xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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