SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1922e5c13f74146dd0597d80e3ac84209ecaad82bc919c9b8edab93062605faf' 
  AND token = '1/Vqs7uy7Csj0ljg3GVlL8IbCPgKeDBMDY+wybd2b/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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